Mostly Metal Servo CNC

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Introduction

When I first started my project to build a CNC, I looked around at existing designs. I looked carefully at Mostly Printed CNC and OX CNC. However, I didn’t like the idea of installing and tightening so many bearings or V wheels. So, I went ahead and designed a CNC based on linear motion ball bearing and smooth rod.

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Design objectives and decisions:

My design objective was to create a relatively stiff DIY 3 axis CNC with no need to drill holes in metal for assembly. I also wanted it to be compact and low profile. Therefore, I decided to use a moving gantry design and use 40mm x 20mm aluminum extrusion for the gantry structure.

For additional challenge, I decided to use servo motor for this project. I’ve chosen a low cost 370 size geared motor with a hall sensor rotary encoder.

Since CNC need a lot more torque than a typical 3D printer,